Installation for vitrification of liquid radioactive wastes, cooled discharged unit and cooled induction melter for the installation

ABSTRACT

The present invention relates to apparatuses for processing homogeneous/heterogeneous radioactive wastes comprising ion-exchange resins. A cooled discharge unit comprises a discharge pipe, a cooling jacket having a U-shaped form in cross section, a collector for feeding a coolant into the jacket, a discharge gate comprising a pipe, on one end of which a cone-shaped tip is positioned, on the other end a lid with an aperture. A cooled induction melter comprises a housing, side walls and bottom of which are made of metal pipes disposed with a gap therebetween and combined by a collector for supplying and discharging the coolant, an inductor positioned adaptable for displacement along the longitudinal axis of the melter and concentrically encompassing the side walls of the housing, the gaps between the pipes of which ensure transparency of the housing for an electromagnetic field of the inductor. The cooled discharge unit is positioned in an aperture, the height of which determines the minimum level of the melt, a portion of the side wall of which is a portion of the side wall of the housing, while another portion faces the melt. An installation for vitrification of liquid heterogeneous radioactive wastes comprises a mixer, a doser of vitrification agent additives, a doser of heterogeneous liquid radioactive wastes, a vessel-accumulator provided with means for homogenizing components, a vortex apparatus, a water-cooled induction melter with a movable inductor, means for filtering waste gas, means for capturing gaseous toxic components.

FIELD OF THE INVENTION

The present invention relates to apparatuses for processing radioactivewastes, and more exactly to an installation for vitrification of liquidhomogeneous/heterogeneous radioactive wastes, including those comprisingion-exchange resins, and also to a cooled discharge unit and a cooledinduction melter for that installation.

BACKGROUND OF THE INVENTION

The invention may be used for hardening liquid radioactive wastes bytransferring them into a solid stable vitriform state suitable forlong-term storage in special storages.

An apparatus is known for supplying different fractions of material(see, for example, U.S. Pat. No. 3,964,892, 1976), comprising a metalhousing having a flat bottoms a refractory reflector positioned on theinner surfaces of the metal housing and the flat bottom, a tubularchannel for discharge of the melt which is positioned in the flat bottomand has a reduced inlet aperture which is closed by means of a rod whichcontrols the output of glass melt, electrodes positioned at an angle of120 degrees, a coil-in-box cooler positioned on the external side of theupper part of the metal housing, a charging device and aturning-positioning mechanism for the rod.

The danger of operation with the apparatus is high because of the highchemical corrosion of the electrodes and the refractory reflector. Thedurability of the apparatus is low because of the burn-out of theelectrodes and the short service life of the refractory reflector.Furthermore, during the discharge there is the danger of the occurrenceof an emergency situation due to the danger of the tubular channeloverheating of its higher chemical corrosion due to the unguaranteedclosure of its reduced inlet aperture because of the higher chemicalcorrosion of the rod and the tubular discharge channel, and also becauseof the danger of the formation of a hard-to-remove glass plug in thetubular discharge channel.

A Joule melter is known for processing radioactive wastes (see, forexample, Europatent 0 137 579, 1985), comprising a steel casting closedat the top by a steel lids the inner surface of which is lined with arefractory material. A jumper is positioned on the bottom part of therefractory material, an electrode of cylindrical shape is positionedaround the jumper, wherein a partition of cylindrical shape having anaperture is positioned inside the electrode, while a starting heater ispositioned on the external side. An outlet pipe for the discharge ofglass melt is located in the center of the bottom part, this pipe beingsimultaneously a second electrode and with its upper part being coveredby a truncated cone with an aperture. A pipe of large diameter for thedischarge of waste gases, an inlet pipe for loading the radioactivewastes and vitrification agents, and also a movable plunger with aconical end-piece ensuring closure of the aperture of the truncated coneare positioned in the steel lid.

Due to the burn-out of the electrode of cylindrical shape, which is apart of the melter housing, and of the second electrode, which is anoutlet pipe for the discharge of the glass melt, and also due to thehigher carrying away of radio nuclides, there is high danger in theoperation of the melter.

Since the jumper has a reduced, temporary service life, the durabilityof melter operation is also low. And due to the greater amount of timenecessary to create a starting melt by means of the starting heater, theproductivity is low

This melter has a narrow field of use due to the fact that it is notpossible to process dehydrated radioactive wastes which containion-exchange resins which during melting may plug the uncooled inletpipe for loading, or to process moist radioactive wastes which containion-exchange resins which may cause short circuiting of the electrodesthrough the moist radioactive wastes which are on the surface of theglass melt.

The danger of the occurrence of an emergency situation during dischargeis also present in the aforesaid melter due to the blocking up of theoutlet pipe for the discharge of melt, the impossibility of clearing itwith a plunger, the danger of its overheating, high chemical corrosion,and also its burning out.

A method and apparatus for vitrification of radioactive materials isknown (see, for example, British patent 1, 239 710, 1971). The apparatusfor vitrification of radioactive materials is a crucible provided with acooling system and with an induction coil connected to a high frequencygenerator. On top the crucible is closed with a metal lid with aperturesto which a calciner and a bunker with vitrification agents, which isprovided with a vibrating feeder, are connected. There is a dischargedevice at the bottom of the crucible which is a discharge pipe providedwith a water-cooled jacket and an inductance coil connected to a highfrequency generator.

There is a high degree of danger during operation of the apparatus dueto high chemical corrosion of the housing of the crucible, the danger ofits mechanical breakdown in the presence of high thermal stresses causedby a large difference between the temperature on the outer and innersurfaces, rind also due to an increase in the degree of votalizaton ofradio nuclides due to the use of a calciner for calcinating radioactivematerials.

Furthermore, the melter has reduced productivity due to the absence of amixer for preliminary mixing of the calcinate of radioactive materialsand the vitrification agents, and also due to the immobility of theinductance coil of the crucible.

The field of use of the apparatus is also limited due to the fact thatit is not possible to process ion-exchange resins which due to theirmelting in the calciner win plug the inlet pipe for loading thecalcinate of radioactive materials.

During the discharge an emergency situation may arise since there is nodischarge gate and this may be the reason for unauthorized discharge ofthe glass melt from the crucible.

SUMMARY OF THE INVENTION

The object of the present invention is to create an installation forvitrification of liquid homogeneous and heterogeneous radioactive wasteswhich may include ionexchange resins, and also radioactive pearlite,activated carbon, sand, in which the use of a water-cooled inductionmelter with a cooled discharge unit and a movable inductor, of anevaporator for dehydrating liquid radioactive wastes, of a vortexapparatus and a separate system for purification of gas make it possibleto carry out the processing of radioactive wastes with minimumcontamination of the environment, eliminating the discharge ofradioactive gaseous and dust-like substances into the atmosphere, toraise the safety of operation of the device, its reliability andproductivity, and also to expand the field of use of the device,ensuring the possibility of processing radioactive wastes which havedifferent compositions.

Another object of the invention is to create a cooled discharge unit forthe water-cooled induction melter, the construction of which would makeit possible to eliminate unauthorized discharge of the vitriform meltfrom the induction melter, to ensure reliable closure of the dischargeunit after discharge, to avoid overheating of the housing of thedischarge unit and to accomplish constant reliable cooling of all theelements of the discharge unit, which in turn makes it possible toeliminate the occurrence of emergency situations during discharge and toenhance the durability.

One more object of the invention is to create a water-cooled inductionmelter in which the use of a cooled discharge unit and also a movableinductor makes it possible to accomplish the processing of moistradioactive wastes and to increase the productivity of the apparatus.

The aforesaid object is achieved in that a cooled discharge unit inaccordance with the invention comprises

a discharge pipe,

a cooling jacket having a U-shaped form in cross section and disposed onsaid discharge pipe,

a lid covering said cooling jacket and said discharge pipe,

a lug in the form of a truncated cone made in said lid from the sidefacing the discharge pipe,

a through cylindric aperture made in said lug, a longitudinal axis ofwhich coinciding with a longitudinal axis of said discharge pipe,

a group of apertures made in said lid and serving to remove a coolantfrom said cooling jacket,

a collector for feeding the coolant into the Jacket and positioned onsaid jacket from the side opposite said lid,

a group of apertures made in said collector for supplying the coolant tosaid cooling jacket,

a discharge gate comprising a pipe, on one end of which, facing saidlug, is positioned a cone-shaped tip, on the other end a lid with anaperture, adjacent which is positioned a pipe for discharge of thecoolant,

a pipe for supplying the coolant, positioned coaxially with said pipe ofthe discharge gate in said aperture of the lid, one end of which beingpositioned adjacent the cone-shaped tip, another end protruding outsidesaid lid.

It is advisable that the cone-shaped tip be made of one piece andconsist of

a first truncated cone having a large base and a smaller base and beingrigidly secured by the large base to said pipe of the discharge gate,

a second truncated cone having a large base and a smaller base, whereinthe large base of said second truncated cone is the smaller base of saidfirst truncated cone,

a third cone having a base which is the smaller base of said secondtruncated cone.

It is advantageous that said first truncated cone and second truncatedcone be made hollow.

It is preferable that the longitudinal axis of said discharge pipe beshifted toward a round portion of said U-shaped jacket.

The stated object is also achieved in that the induction melter, inaccordance with the invention, comprises

a housing, side walls and bottom of which are made of metal pipesdisposed with a gap relative to each other and combined by a collectorfor supplying and discharging a coolant,

a hollow cooled lid provided with pipes for supplying and dischargingthe coolant,

pipes for loading a mixture of liquid radioactive wastes andvitrification agents, pipes for discharge of waste gases, pipes forreturning filtrate and a port for technological servicing positioned insaid lid,

a bushing positioned in said lid, the geometrical axis of which isparallel to the axis of said housing and the length of which is somewhatgreater than the thickness of said lid,

a discharge gate positioned in said bushing and provided with a drivefor vertical displacement,

at least one pipe for positioning sensors of technological parameters ofthe process,

an inductor positioned adaptable for displacement along the longitudinalaxis of said melter and concentrically encompassing said side walls ofthe housing, the gaps between the pipes of which ensuring transparencyof the housing for an electromagnetic field of the inductor, the shortinductor serving to create maximum magnetic field strength directlyadjacent the moving surface of a melt produced during the input andmelting of the mixture of liquid radioactive wastes and thevitrification agents,

a means for moving said inductor along the longitudinal axis of saidmelter,

an aperture in said bottom of the housing directly adjacent said wall,

a cooled discharge unit positioned in said aperture, the height of saidcooling jacket of said discharge unit determining the minimum meltlevel, a portion of said cooling jacket being a part of the side wall ofthe housing and another portion of said cooling jacket facing the melt.

It is advisable that said pipe for discharge of waste gases contain acooling jacket

It is usefull that said port for technological servicing be providedwith a cooled lid.

It is advantageous that sensors selected from the following group beused as sensors of technological parameters at least two melt surfacetemperature sensors, a sensor of the pressure of gases above the meltsurface, a sensor of the temperature of gases above the melt surface,and a picture monitor.

The object is also achieved in that an installation for vitrification ofliquid radioactive wastes, in accordance with the invention, comprises

a mixer provided with a means for mixing components, having an input, asecond input, and an output,

a doser of vitrification agent additives, having an output coupled tosaid input of said mixer,

a doser of heterogeneous liquid radioactive wastes, connected by itsoutput to said second input of said mixer,

a vessel-accumulator provided with a means for homogenization ofcomponents, having an input coupled to said output of said mixer and anoutput,

a vortex apparatus serving to process the mixture of liquid radioactivewastes in a vortex layer, having an input connected to said output ofsaid vessel-accumulator, and an output provided with a doser,

a cooled induction melter with a movable inductor, having a first inputconnected to said output of said doser of the vortex apparatus, a secondinput, a first output for discharge of obtained melt of vitrifiedradioactive wastes and a second output for discharge of waste gases,

a means for filtering waste gas having successively mounted coarsefilters and fine filters, having an input connected to said secondoutput of said melter, and an output,

a condenser for condensing liquid vapors released from said melter,having an input connected to said output of said means for filteringwaste gas and an output,

a means for capturing gaseous toxic components, including an absorber,heater, catalytic reactor and condenser, and having an input coupled toan output of said condenser, and an output coupled to the atmosphere.

The object is a)so achieved in that an installation for vitrification ofliquid radioactive wastes, in accordance with the invention, comprises

a vessel for receiving a dosed portion of homogeneous liquid radioactivewastes and collecting concentrated homogeneous liquid radioactivewastes, the vessel being linked to a collector of liquid radioactivewastes and having first and second inputs and an output,

an evaporator having an input, provided with a gate and coupled to saidoutput of said vessel to receive radioactive wastes, and having a firstoutput coupled to second input of said vessel to receive radioactivewastes, and a second output,

a separator for separating droplets of liquid from the steam-gaseousmixture, having an input connected to said second output of saidevaporator, and having an output,

a condenser for condensing steam having an input coupled to said outputof said separator, and an output for the discharge of a condensate,

a mixer provided with a means for mixing components, having an inputprovided with a gate and connected to said output of said vessel toreceive concentrated homogeneous liquid radioactive wastes, a secondinput, third input and output,

a doser of vitrification agent additives, having an output coupled tosaid second input of said mixer,

a doser of heterogeneous liquid radioactive wastes, connected by itsoutput to said third input of said mixer,

a vessel-accumulator provided with a means for homogenization ofcomponents, having an input coupled to said output of said mixer and anoutput,

a vortex apparatus serving to process the mixture of liquid radioactivewastes in a vortex layer, having an input connected to said output ofsaid vessel-accumulator, and an output provided with a doser,

a cooled induction melter with a movable inductor, having a first inputconnected to said output of said doser of the vortex apparatus, a secondinput, a first output for discharge of obtained melt of vitrifiedradioactive wastes and a second output for discharge of waste gases,

a means for filtering waste gas having successively mounted coarsefilters and fine filters, having an input connected to said secondoutput of said melter, and an output,

a second condenser for condensing liquid vapors released from saidmelter, having an input connected to said output of said means forfiltering waste gas and an output,

a means for capturing gaseous toxic components, including an absorber,heater, catalytic reactor and condenser, and having an input coupled toan output of said second condenser, and an output coupled to theatmosphere.

It is advisable that said coarse filter be coupled to said water-cooledinduction melter.

BRIEF DESCRIPTION OF THE DRAWINGS

Further the invention will be explained by a description of preferablevariants of its relation with references to the accompanying drawings inwhich:

FIG. 1 shows a water-cooled discharge unit (longitudinal section), inaccordance with the invention;

FIG. 2 shows a section along line II--II in FIG. 1, in accordance withthe invention;

FIG. 3 shows a general view of the discharge pipe, in accordance withthe invention;

FIG. 4 shows a cone-shaped tip (longitudinal section), in accordancewith the invention,

FIG. 5 shows a general view of a cooled induction melter, in accordancewith the invention,

FIG. 6 shows a diagram of the installation for vitrification of liquidradioactive wastes, in accordance with the invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

A cooled discharge unit 1 (FIG. 1) comprises a discharge pipe 2, acooling jacket 3 having a U-shaped form in cross section (FIG. 2) anddisposed on the discharge pipe 2 FIG. 1). A lid 4 doses the coolingjacket 3 and the discharge pipe 2. A lug 5 in the form of a truncatedcone from the side facing the discharge pipe 2 is made in the lid 4. Athrough cylindrical aperture 6 is made in the lug 5, the longitudinalaxis a-a of which is aligned with the longitudinal axis of the dischargepipe 2.

Apertures 7 are made in the lid 4 (FIG. 3), the apertures serving toremove a coolant from the cooling jacket 3. A collector 8 for feedingthe coolant into the jacket is positioned on the jacket from the sideopposite the lid 4, i.e. in the lower part of the discharge unit 1.Apertures 9 are made in the collector 8 for supplying the coolant to thecooling jacket 3.

A discharge gate 10 (FIG. 1) comprises a pipe 11, on one end of which,facing the lug 5, is positioned a cone-shaped tip 12, while on the otherend a lid 13 with an aperture 14 is disposed, directly adjacent which ispositioned a pipe 15 for discharge of the coolant. A pipe 16 forsupplying the coolant is positioned coaxially with the pipe 11 of thedischarge gate in the aperture 14. One end of the pipe 16 is positioneddirectly adjacent the cone-shaped tip 12, while the other end protrudesoutside the lid 13.

The cone-shaped tip 12 (FIG. 4) is made of one piece and consists of afirst truncated cone 17 rigidly secured by the large base to the pipe 11of the discharge gate, a second truncated cone 18, the large base ofwhich is the smaller base of the first truncated cone 17, and a thirdcone 19, the base of which is the smaller base of the second truncatedcone 18.

The first truncated cone 17 and the second truncated cone 18 are hollow.

The longitudinal axis a-a of the discharge pipe 2 is shifted toward theround portion of the U-shaped jacket 3 (FIG. 2).

A cooled induction melter 20 (FIG. 5) comprises a housing 21, side walls22 and a bottom 23 of which are made of metal pipes disposed with a gap24 and combined by a collector 25 for supplying and discharging acoolant. The melter comprises a hollow cooled lid 26 provided with pipes27, 28 for supplying and discharging the coolant, respectively. Pipes 29for loading a mixture of liquid radioactive wastes and vitrificationagents, pipes 30 for discharging waste gases, pipes 31 for returningfiltrate and a port 32 for technological servicing are disposed in thelid 26. A bushing 33 is also disposed in the lid 26, the geometricalaxis of the bushing being parallel to the is of the housing 21 and thelength of the bushing is somewhat greater than the thickness of the lid26. A discharge gate 10 is positioned in the bushing and is providedwith a drive (not shown in FIG. 5) for vertical displacement.

There are two pipes 34 provided in the lid 26 for positioning sensors ofthe technological parameters of the process (not shown in FIG. 5). Atleast two melt surface temperature sensors, a sensor of the pressure ofgases above the melt surface, a sensor of the temperature of gases abovethe melt surface and a picture monitor are used as sensors of thetechnological parameters of the process.

An inductor 35 is positioned adaptable for displacement along thelongitudinal axis of the melter 20 and concentrically encompasses theside walls 22 of the housing 21, the gaps 24 between the pipes of whichensure transparency of the housing 21 for an electromagnetic field ofthe inductor 35. The purpose of the displaceable inductor is to createmaximum strength of the electromagnetic field directly adjacent a movingsurface 36 of a melt 37 produced during the input and melting of amixture of liquid radioactive wastes and vitrification agents. A meansis provided for moving the short inductor along the longitudinal axis ofthe melter (not shown in FIG. 5).

An aperture for disposal of the cooled discharge unit 1 is made in thebottom 23 of the housing directly adjacent the wall 21. The height ofthe cooling jacket 3 determines the minimum level of the melt 37. Aportion of the side wall of the cooling jacket 3 is a portion of theside wall 22 of the housing 21 and another portion of the cooling jacket3 faces the melt 37.

The pipe 30 for discharge of waste gases contains a cooling jacket.

The port 32 for technological servicing is provided with a cooled lid 38

An installation for vitrification of liquid radioactive wastes comprisesa vessel 39 (FIG. 6) for receiving a dosed portion of liquid radioactivewastes and collecting concentrated homogenized liquid radioactivewastes, an input 40 of the vessel being coupled to an output 41 of acollector 42 of liquid radioactive wastes.

An evaporator 43 is provided with a gate 44 and is coupled to an output45 of the vessel 39, wherein an output 46 of the evaporator 43 iscoupled to a second input 47 of the vessel 39. A separator 48 serves toseparate droplets of liquid from a steam-gas mixture, an input 49 ofwhich is connected to a second output 50 of the evaporator 43.

A condenser 51 for condensing steam has an input 52 coupled to an output53 of the separator 48 and has an output 54 for discharge of acondensate.

The installation contains a mixer 55 provided with a means 56 for mixingcomponents and having an input provided with a gate 57, connected to theoutput 45 of the vessel 39.

A doser 58 of vitrifying additives is coupled by an output 59 to asecond input 60 of the mixer 55. A doser 61 of heterogeneous liquidradioactive wastes is connected by an output 62 to a third input 63 ofthe mixer 55.

There is a vessel-accumulator 64 provided with a means 65 forhomogenization of components, an 66 of which is connected to output 67of the mixer 55.

A vortex apparatus 68 serves to process the mixture of liquidradioactive wastes in a vortex layer and is connected by input 69 tooutput 70 of the vessel-accumulator 64, while output 71 of the vortexapparatus 68 is provided with a doser 72.

A water-cooled induction melter with a movable inductor 20 has a firstinput 29 connected to an output 73 of the doser 72 of the vortexapparatus 68, a first output 74 for discharge of the obtained melt ofvitrified radioactive wastes, and a second output 30 for discharge ofwaste gases.

The installation also comprises a means 75 for filtering waste gashaving successively mounted coarse filters 76 and fine filters 77,wherein the input 78 of the means 75 is connected to the second output30 of the melter 20.

A second condenser 79 serves for condensing liquid vapors released fromthe melter 20 and has an input 80 connected to an output 81 of the means75 for filtering waste gas.

A means 82 for capturing gaseous toxic components includes an absorber83, a heater 84, a catalytic reactor 85 and a condenser 86, and has aninput 87 connected through a vessel 88 of a condenser of a filteringsystem to an output of the second condenser 79, and an output 89 coupledto the atmosphere.

The coarse filter 76 is coupled by output 90 to the pipe 31 of thecooled induction melter 20.

The installation operates in the following manner,

A portion of homogenized liquid radioactive wastes comprising cations ofalkali and alkali-earth metals, for example, sodium, potassium, calcium,magnesium, and also cations of aluminum and iron and anions OH, SO₄, Cl,CO₃, PO₄ NO₃, and radioactive elements, e.g., strontium Sr, cesium Cs,cobalt Co and others from the collector 42 (FIG. 6) of liquidradioactive wastes from the output 41 are fed through input 40 to thevessel 39 for receiving a dosed portion of homogenized liquidradioactive wastes and collecting concentrated homogenized liquidradioactive wastes. Then the gate 58 is closed, the gate 44 opened andthe evaporator 43 is activated. Evaporation is carried out bycirculating liquid wastes from the evaporator 43 to the vessel 39 andback.

When the necessary degree of concentration, 900-1100 g/l, is reached, aportion of the concentrated homogenized liquid radioactive wastes iscollected in the vessel 39. The waste steam-gas Be through outlet 50 ofthe evaporator 43 is fed to the separator 48 where it is cleansed ofdroplets of liquid. Then the steam-gas mixture is directed to thecondenser 51, where condensation of the steam takes place. After thatthe gaseous phase, having a volume activity according to cesium-137 andto plutonium-239 within prescribed limits, is released into theatmosphere.

After a portion of concentrated liquid homogenized radioactive wasteshas been collected in the vessel 39, the gate 44 is closed and gate 58opened. The concentrated wastes are fed from the vessel 39 through theoutput 45 and the gate 58 into the mixer 55, after which the gate 58 isclosed, gate 44 is opened and a new portion of homogeneous liquidradioactive wastes is fed into the vessel 39 to carry out the next cycleof concentrating and collecting radioactive wastes

Simultaneously with concentrated homogenized liquid radioactive wastes,a portion of vitrifying (flowing) additives comprising oxides ofsilicon, boron, aluminum and calcium is fed through the input 60 fromthe doser 58, and through the input 63--a portion of heterogeneousliquid radioactive wastes comprising radioactive ion-exchange resins,radioactive pearlite, radioactive activated carbon and radioactive soil.The humidity of the mixture is from 0.0001 to 60% in an amount from 1 to9 parts by weight to a part by weight of the mixture of concentratedhomogenized liquid radioactive wastes with fluxing additives. The ratioof the fluxing additives and concentrated liquid radioactive wastes isfrom 30 to 50% by weight of dry salts, where from 42 to 77% are moistsalts and from 58 to 23% of fluxing additives. A datolite concentrate,boric acid, calcium metaborate, bentonite, quartz sand can be used asthe fluxing additives. The following ratio of concentrated homogenizedliquid radioactive wastes and fluxing additives is a possible concreteexample: 52% of concentrated salts, 48% of fluxing additives, including24% of datolite concentrate, 12% of quartz sand and 12% of bentoniteclay The obtained mixture is mixed in the mixer 55 using the means 56for mixing and is fed through the output 67 to the vessel-accumulator64.

Where it is only necessary that processing of the liquid heterogeneousradioactive wastes be carried out, the composition of the vitrifyingadditives is corrected.

A starting glass melt is created in the cooled induction melter 20 witha movable inductor, after which the radioactive mixture is fed throughthe output 70 into the vortex apparatus 68 where it is processed in thevortex layer. Activation of the surface of the solid phase of themixture occurs during the processing, the mixture itself is subjected tothe action of a magnetic field, hydrodynamic and acoustic impacts,electrization, local high temperatures and pressures.

The processed mixture from the vortex apparatus 68 through the doser 72is fed to the input 29 of the cooled induction melter with a movableinductor 20 During the process of feeding, the doser 72 carries outautomatic adjustment of the position of the displaceable inductor 20depending on the amount of the loaded mixture. The radioactive mixturein the inductor 20 is subjected to heating and melting while oxylith issimultaneously fed thereto and is converted into a melted vitric form.After that the output 74 for discharge of the melt is opened and themelt is discharged into receiving containers 91.

The waste gases are discharged from the melter 20 through the output 30and directed to the input 78 of the means 75 for filtering waste gases.The gases purified by the filters are fed through the output 81 to theinput 80 of the condenser 79, in which condensation of vapors of theliquid takes place. The waste gases and the waste liquid condensate fromthe condenser 79 are fed into the vessel 88, where separation of thegaseous and liquid fractions takes place. Gas from the vessel 88 is fedto the input 87 of the means 82 for capturing gaseous toxic components,the purified gas is discharged into the atmosphere through the output89. As an example, the following concrete parameters of the waste gascan be indicated. The concentration of nitrogen oxides is less than 10mg/m³, the concentration of hydrogen chloride is less than 10 mg/m³, theconcentration of sulfur oxides is less than 30 mg/m³, the volumeactivity according to cesium-137 is less than 1000 Bk/m³, toplutonium-239--less than 0.1 Bk/m³.

Reduction of the residual toxic nitrous gases to nitrogen takes placeafter the absorber 83 in the catalytic reactor 85, wherein the heater 84hinders the formation of a condensate and ensures reliability ofoperation of the catalytic reactor 85.

The filtrate through the output 90 of the coarse filter of the means 75is directed to the cooled induction melter 20. The condensate from thevessel 88 is directed as replenishment to the washing liquid circulationsystem of the absorber 83 of the means 82, and the spent washing liquidwith specific activity according to cesium-137 which is less than theprescribed limit is released.

Subsequent portions of the initial homogeneous and heterogeneous liquidradioactive wastes are directed for further processing according to theprocess described above.

The cooled induction melter 20 with the movable inductor operates in thefollowing manner.

A portion of a mixture of vitrification agents, heterogeneous liquidradioactive wastes and a concentrate of homogenized liquid radioactivewastes is fed by means of the doser 73 to the melter 20 with thepreliminary created starting melt of the glass melt and with thedischarge gate 10 closed. Wherein the doser depending on the amount ofthe mixture being fed carried out automatic adjustment of the mostoptimum positioning of the movable short inductor 35, i.e. at whichmaximum efficiency is achieved.

The mixture of the aforesaid components will be fed until the wholeworking volume of the melter 20 is filled with glass melt being formed.Then the glass melt is held at a temperature of 900-1300 degreesCentigrade in order to complete the processes of vitrification, afterwhich the aperture 6 is opened and a discharge into receiving containers91 takes place. After discharge the aperture 6 is closed and the nextcycle of operation of the melter 20 is carried out.

Since the lid 4 (FIG. 5) of the cooled discharge unit 1 is positionedhigher than the level of the bottom of the cooled induction melter 20,some amount of glass melt remains therein after each discharge and thisamount is used as a starting melt in each subsequent cycle ofvitrification.

The cooled discharge unit 1 (FIG. 1) operates in the following manner.

In the closed state of the discharge unit 1, the pipe 11 of thedischarge gate 10 is disposed inside the through cylindrical aperture 6of the lug 5, fully covering its cross section, wherein the cone-shapedtip 12 of the discharge gate 10 is positioned inside the discharge pipe2 below the lug 5.

After the cycle of vitrification of liquid radioactive wastes iscompleted, the discharge gate 10 is raised by means of a movingmechanism (not shown in FIG. 1) until the through cylindrical aperture 6of the lug 5 is completely open. The discharge unit 1 is in the openstate during the whole period of discharging the glass melt, after whichthe discharge gate 10 returns to the initial position. Due to theaforesaid configuration of the cone-shaped tip 12, a guaranteed removaltakes place of the glass plug which is formed after discharge from theaperture 6 is over.

Cooling of the discharge unit 1 ensures the reliability of itsoperation, since otherwise the discharge unit 1 is subjected tointensive corrosion and may break down. The "U"-shaped cooling jackethinders the danger of the occurrence of an emergency situation, since ifthere are any units in the configuration or, what is even worse, cornerjoints, at the places where they are positioned overheating zones areformed, as a consequence of which destruction occurs. With any otherform of cooling jacket, without corner joints, zones of localoverheating will be formed in the near-wall zone due to the compactionof the lines of force of the electromagnetic field. A consequence ofthis will be that a larger amount of aerosols and volatile forms ofradio nuclides will be carried away from the overheating zone, whichdoes not ensure the effect of improving the safety of operation of theapparatus.

Inclusion of the vortex apparatus in the construction of theinstallation and also the use of the movable inductor and cooledinduction -melter make it possible to reduce the time necessary forvitrification of radioactive wastes by the obtainment of a vitrifiedproduct with a higher degree of dispersion and activity on its surfacein the vortex apparatus, stabilization of the working temperature of thesurface of the melt due to the presence of the movable inductor, andalso by intensification of self-stirring of the glass melt in the cooledinduction melter.

The construction and arrangement of the cooled discharge unit in thecomposition of the cooled induction melter with the movable inductoralso promotes enhancement of productivity of the device, due to theincomplete discharge of the glass melt, the residue of which is used asthe staring melt in each subsequent cycle of vitrification ofradioactive wastes, which reduces the time during which it is carriedout as compared with known methods.

As a result, the productivity of the installation increases by 1.2-1.3times. Furthermore, the use of the cooled induction melter makes itpossible to substantially reduce its corrosion with the glass melt dueto the preventive action of the lining slag layer, thus enhancing thesafe operation of the installation.

The arrangement of the condenser in the scheme for purification of gasesreleased form the melter after the means for filtration of waste gasesmakes it possible to obtain a practically non-radioactive condensatewith a specific radioactivity according to cesium-137 which is less than100 Bk/kg, without the need for feeding it into the collector ofradioactive liquid wastes for reprocessing, and this also increases theproductivity of the installation.

The possibility for supplying heterogeneous liquid radioactive wastescomprising radioactive ion-exchange resins for vitrification withoutgoing through the evaporator excludes a break-down due to the danger ofthe resin melting and ensures expansion of the possibility of using theinstallation for processing radioactive wastes of different composition.The separate execution of the unit for rendering wastes harmless ensuresthe operation of the installation as a whole, since the ingress of thesteam-gas mixture, containing a greater amount of moisture, into themeans for filtering waste gases from the evaporator results in a rapidbreakdown of that means.

Use of the absorber and the catalytic reactor ensures reduction of thecontent of chlorine-containing and nitrose components in the gasesdischarged into the atmosphere after purification to the maximumpermissible limits. For example, the concentration of nitrogen oxides isless than 10 mg/m³, the concentration of hydrogen chloride is less than10 mg/m³, the concentration of sulfur oxides is less than 30 mg/m³.

We claim:
 1. An installation for vitrification of liquid heterogeneousradioactive wastes comprisinga mixer provided with a means for mixingcomponents, having an input, a second input, and an output, a doser ofvitrification agent additives, having an output coupled to said input ofsaid mixer, a doser of heterogeneous liquid radioactive wastes,connected by its output to said second input of said mixer, avessel-accumulator provided with a means for homogenization ofcomponents, having an input coupled to said output of said mixer and anoutput, a vortex apparatus serving to process the mixture of liquidradioactive wastes in a vortex layer, having an input connected to saidoutput of said vessel-accumulator, and an output provided with a doser,a cooled induction melter with a movable inductor, having a first inputconnected to said output of said doser of the vortex apparatus, a secondinput, a first output for discharge of obtained melt of vitrifiedradioactive wastes and a second output for discharge of waste gases, ameans for filtering waste gas having successively mounted coarse filtersand fine filters, having an input connected to said second output ofsaid melter, and an output, a condenser for condensing liquid vaporsreleased from said melter, having an input connected to said output ofsaid means for filtering waste gas and an output, a means for capturinggaseous toxic components, including an absorber, heater, catalyticreactor and condenser, and having an input coupled to an output of saidcondenser, and an output coupled to the atmosphere.
 2. An installationfor vitrification of liquid radioactive wastes comprisinga vessel forreceiving a dosed portion of homogeneous liquid radioactive wastes andcollecting concentrated homogeneous liquid radioactive wastes, thevessel being linked to a collector of liquid radioactive wastes andhaving first and second inputs and an output, an evaporator having aninput, provided with a gate and coupled to said output of said vessel toreceive radioactive wastes, and having a first output coupled to secondinput of said vessel to receive radioactive wastes, and a second output,a separator for separating droplets of liquid from the steam-gaseousmixture, having an input connected to said second output of saidevaporator, and having an output, a condenser for condensing steamhaving an input coupled to said output of said separator, and an outputfor the discharge of a condensate, a mixer provided with a means formixing components, having an input provided with a gate and connected tosaid output of said vessel to receive concentrated homogeneous liquidradioactive wastes, a second input, third input and output, a doser ofvitrification agent additives, having an output coupled to said secondinput of said mixer, a doser of heterogeneous liquid radioactive wastes,connected by its output to said third input of said mixer, avessel-accumulator provided with a means for homogenization ofcomponents, having an input coupled to said output of said mixer and anoutput, a vortex apparatus serving to process a mixture of liquidradioactive wastes in a vortex layer, having an input connected to saidoutput of said vessel-accumulator, and an output provided with a doser,a water-cooled induction melter with a movable inductor, having a firstinput connected to said output of said doser of the vortex apparatus, asecond input, a first output for discharge of obtained melt of vitrifiedradioactive wastes and a second output for discharge of waste gases, ameans for filtering waste gas having successively mounted coarse filtersand fine filters, having an input connected to said second output ofsaid melter, and an output, a second condenser for condensing liquidvapors released from said melter, having an input connected to saidoutput of said means for filtering waste gas and an output, a means forcapturing gaseous toxic components, including an absorber, heater,catalytic reactor and condenser, and having an input coupled to anoutput of said second condenser, and an output coupled to theatmosphere.
 3. An installation of claim 2 wherein said coarse filter iscoupled to said water-cooled induction melter.